DE2253787A1 - LEVELING DEVICE FOR A ROAD CONSTRUCTION MACHINE - Google Patents

Description

BARBER-GREENE COMPANY
400 North Highland Avenue
Aurora, Illinois V.St.A.

Level reference device for a road construction machine

The invention relates to a mobile level reference device, especially for a road construction machine used, for example, for paving a road. at the use * of an asphalt paving machine in road construction is advantageous "a level reference device used, which Inclination direction values can be taken. As known is, such an asphalting machine, which is provided with an external level reference device, has a automatic adjustment device. This device has a sensor or button, the one outside lying Touches the reference thread or side wire. The outside one The reference device forms a reference plane that is independent of the road construction machine, the reference plane must be aligned before the paving machine begins to operate at any point in its port trajectory. The sensor or button actuates a generally hydraulically driven control device for control purposes of the adjustment angle in which the articulation points of the arms, the carry, raised or lowered the balancing device

^{will be} \ 309022/0767

- 1 _ ORIGINAL INSPECTED

The external reference plane can be formed by a thread or a string wire that is parallel aligned in relation to the desired level. It can also be an existing curb or an adjacent one Road surface parallel to the desired level are used as the external reference plane. A movable level reference device may be desirable to use that has components that form a reference line or reference plane. Such a device is towed forward with the road construction machine and rests on the subsoil or the adjacent surface. The term "subsoil" refers to the road surface that the road surface is paved by the road construction machine is to receive, be it bituminous material or leveled earth or a layer of one arranged on the ground Aggregate.

The mobile level reference device described can be found in can be divided into two different types. The first type consists of a beam, a runner or straight edge, of certain fixed dimensions, for example at least equal to the span of a track or the wheels of the Road construction machines that span the hollows and depressions and stretch bumps by placing on a Side of the unevenness a bevel is arranged, creating a minimum material thickness over such an unevenness is needed. The second type of device under consideration can can be characterized as an averaging device. This device can have a carrier on which two or more wheels or runners touching the ground are arranged or can be made from a flexible tube or There are carriers, with a tensioned thread or side wire being provided in each case. If such a device is mounted on wheels or runners, each wheel or runners can be individually linked to a lever system, so that each wheel or skid is in contact with the

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reason remains, while the carrier provides a support for the Adjusting device forms. This type of device averages the profile slope over which it is pulled, whereby it fills depressions or depressions and reduces the height of bumps by placing thinner layers of material on top of them Tips of these bumps are applied.

In the past, such devices were constructed according to a precisely defined geometric configuration. Included Great importance had to be attached to uniform wheels or uniform spacing of runners. Although these devices generally are satisfactory, they do not work as accurately as is desirable because they do not create a road surface, in which the hollows are optimally filled and the heights of the unevenness are optimally reduced.

The invention is primarily directed to providing a new and improved level reference device which Has supporting parts supporting on the ground, which are in the longitudinal direction of the device at any chosen intervals are arranged.

The invention is also directed to a mobile level reference device of the type described above, in which the wheels in contact with the ground are arranged in this way are that they exert an equal influence on the sensing element of the balancing device.

The present invention relates to a mobile level reference device, which actuates the balancing device with such a high accuracy that the troughs and depressions be filled with asphalt material and the bumps are covered with such a material, so that an optimal road profile results. The present invention also relates to a mobile level

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traction device in accordance with certain practical Considerations has optimal frequency responses, so that the end of the probe arm of the balancing device a way or a Profile describes in remarkable close correspondence with the mean profile of an uneven ground, so that the road construction machine thereby produces a drivable surface with a desired contour. This is achieved by that the wheels or runners touching the ground are arranged at any distance. In a preferred embodiment According to the invention, the wheels or runners are arranged in such a way that all wheels or runners are the same Exert influence on the sensor.

The invention also consists in that horizontally extending, articulated beams are arranged on an asphalt road construction machine on one side and are adjacent extend in the longitudinal direction of the traveling direction of the road construction machine. A string wire is used as the level reference plane arranged on the carriers and is in physical contact with the sensor of a balancing device. A multitude of individual runners touching the ground is provided on the girders to support the same, with these Runners are arranged in the longitudinal direction of the carrier at any chosen intervals. The runners are in pairs on the base bars articulated, the base supports being rotatably supported in the middle of their longitudinal extension.

Further features, details and advantages of the invention emerge from the following description of an exemplary embodiment based on the drawing. Show in it:

Fig.l is a side view of a mobile level reference device according to the invention, in which the road construction machine connected to the device in dashed lines Lines is shown;

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2 shows a representation of a subsurface profile and three Roadway profiles that are known by the appropriate use of the device according to the invention and two Devices were obtained;

3a and 3b each part of an enlarged side view the mobile level reference device according to Figure 1;

4 is an enlarged partial view of a typical connection point between a runner in contact with the ground and the connected base support;

FIG. 5 shows a section along the line 5-5 according to FIG. 4;

Fig. 6 is a diagram in which certain curves are shown, used for the analytical evaluation of the sensitivity of the preferred device according to the invention will;

7 shows a representation in which frequency responses ift of the invention Device are shown and

8 shows a representation in which frequency responses of the invention Device in comparison to the frequency responses of other level reference devices are shown.

In the figure! is a mobile level reference device according to the invention 10 shown. The paving apparatus 12, which is not the invention, is known in the art and is self-propelled Vehicle formed, which is mounted on suitable wheels or a crawler track with endless caterpillars. The road construction machine has a container 13 for receiving the road paving material. The road construction machine has furthermore a balancing device 14 which is rotatably articulated at the freely suspended ends of a pair of pulling arms 15

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is. In the figure, only one pull arm is shown in dashed lines. The road construction machine is provided with a suitable control system for raising and lowering the front ends of the towing arms arranged pivot points. When the front ends of the pulling arms are raised, the leveling device climbs 14 gradually a slope formed by the road surface material until the adjustment device 1 * 1 as a result aligns itself flat again on its own movement, creating a thicker layer of material. Lowering the front ends of the pulling arms does the opposite and thereby a thinner layer of paving material is achieved.

The road construction machine has an automatically acting balancing device, which according to the device according to U.S. Patent 3,285,148. One Such a balancing device has a probe 16 with a probe arm 17. The probe arm 17 feels or touches one Reference wire which is arranged in a predetermined position and which is independent of the road construction machine on the level reference device is attached according to the invention. The location of the reference wire is established before the road construction machine begins to work at a certain point in its trajectory, which runs from right to left in Pig.l. The sensor l6 or probe arm 17 actuate the balancing device 14, thereby causing the pulling arms 15 to be independent of any external reference line or plane Movement of the road construction machine to follow and creating a substantially equal angular relationship between the adjustment device and the reference line can be achieved.

The illustrated in Fig.l, 3a and 3b according to the invention Mobile level reference device 10 has three articulated supports 18, 19 and 20, the support 19 on the other two Supports is articulated by means of suitable articulated connections 21, 22. The carriers 18 and 20 carry in the longitudinal direction

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device seen in the middle corresponding stands 24, 25, to which a thread or a string wire 28 is attached. This string wire is in contact with the feeler arm 17 and forms the external reference line described above.

The level reference device 10 has a pair of base supports 30, 31 »which, viewed in the longitudinal direction, are in their center at the adjacent ends of the beam 18 by means of articulated connections 32, 33 are attached. In the same way, the level reference device has a further pair of base supports 35 »36, with these girders in their center, from the side seen, by means of the articulated connections 38, 39 are connected to the adjacent ends of the beam 20.

A pair of runners 41, 42 touching the ground are movable at the ends of the base support 30 by means of corresponding Articulated connections 43, 44 articulated. The is accordingly Basic support 31 by means of corresponding articulated connections 48, 49 arranged on a pair of runners 46, 47. In the same way the base support 35 is mounted on a pair of runners 51, 52 by means of corresponding articulated connections 53, 54. In the end is the base support 36 on the runners 56, 57 by means of corresponding articulated connections 58, 59 are arranged.

The runner 4l shown in Figure 4 has a with it below and outwardly extending side parts 60a, 60b provided plate part 60, wherein the side parts are attached to the parts 6la, 6lb extending in the longitudinal direction of one provided with a part 6lc extending in the transverse direction Connect the bracket. It goes without saying that the constructions of the other runners are identical to the construction the above-described runner 41 are.

The base bracket 30 has an upright support 62, polygamy is attached to a rod 63, which with its front

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Ren end is articulated movably on a support Sh of the road construction machine 12 (see Fig.l). The mobile level reference device 10 according to the invention is pulled by the road construction machine and extends on one side of the road construction machine along the direction of travel of the machine.

According to an essential feature of the invention, the runners are not at the same distance from one another along the Level reference device or arranged according to a certain geometric design, but they are in attached at any distance. These arbitrary spacings can be made, for example, by using usual Data tables are derived or some other method of obtaining the values.

In order to achieve the spacing between the runners, certain through practical considerations given parameters are observed. These parameters consist of the overall length of the level reference device, the number of parts in contact with the ground and the smallest distance between these parts or runner, which in turn is influenced by the length of each runner. In the preferred embodiment of the Level reference device according to the invention eight runners are provided, the distance between the leading and center-to-center dragged skids are approximately 30 feet (9.14 meters).

In accordance with the aforementioned factors, the following values were obtained from a table for the distances between the eight runners taken from the level reference device according to the invention: 66, 96, 138, 198, 252, 282, 36O. This arbitrary selected numbers, which are drawn in Figures 3a and 3b, denote the following, between their corresponding axes of rotation measured distances of the runners

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Continuous from left to right: 5.11 ft, 3.40 ft, 4.22 ft, 5.68 ft, 3.82 ft, 2.9o ft, 5.22 ft (1.56 m, 1.04 m, 1.29 m, 1.73 m, 1.16 m, 0.88 m, 1.59 m). Of course, each must be arbitrary Selected combination of numbers which is realized in the construction of a level reference device according to the invention will be selected so that there is sufficient free space between the adjacent wheels or runners is.

The base supports are necessarily of different lengths, so that these can be chosen at any distance between the runners can be realized. However, each base carrier is articulated on the carrier in its center when viewed from the side l8 or 20 attached.

The frequency response of the level reference device according to the invention has been determined analytically. A sinusoidal oscillation was selected because it corresponds to the bumps or irregularities, which are generally present in an average subsurface, comes very close. The sine wave represents the profile of a subsurface better than any other purely mathematical puncture. the Use of a sinusoidal oscillation to examine the frequency response the level reference device according to the invention is entitled. Using a sine wave to approximate the frequency response is important in the design and Design of other systems, such as an automatic control system, is common practice.

In FIG. 6 there is a background in the form of a sinusoidal oscillation shown. The amplitude of the sinusoidal oscillation forms the maximum deviation from the mean floor area. · The term "vibration or wave" means the distance between two identical points on the sinusoidal oscillation - in Fig. 6 corresponds to a whole sinusoidal oscillation

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■ - 9 -

the distance from a maximum amplitude of a bump in the ground to the maximum amplitude of an adjacent one Unevenness.

In the two representations of FIGS. 7 and 8, the ordinate values are shown as the ratio of the output variable to the input variable. The optimal ratio is zero; this corresponds to a road profile that is exactly parallel to the mean slope of the lower floor. A ratio of the output variable to the input variable of 1.0 does not correspond to a mean value determination, whatever results in the carriageway level following the underground profile. For example, FIG. 6 shows in a dashed line a ratio of the output variable to the input variable of 0.5. Such a ratio indicates that the unevenness of the road profile has been lowered to an extent of 50% and the hollows have been filled.

7 shows the frequency responses determined by a computer the level reference device. This diagram shows the relationship between the output variables and the input variables from a minimum sine wave of 2.0 to a sine wave length of infinity. The term "wavelength" can be expressed by the following formula:

- 36o χ parameter (CD.)

"Angle as a function of the parameter

The parameter (CD.) Is formed from the distance between the axis of rotation of the leading runner and the axis of rotation of the trailed runner of the level reference device. The angle as a function of the parameter CD. is expressed by the relationship between the parameter CD. and the size of the wave. For example, corresponds to a level reference device with a characteristic size of 30 feet (9.14 meters) a shaft of 30 feet, a borehole width of 360 °; and

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- ίο -

4i

225378?

a device with a characteristic of 30 feet on a 15 foot shaft, an arc width of 720 °. In FIG. 7, the abscissa values correspond to the arc width in degrees.

8 shows four frequency responses determined by a computer. The frequency responses of the preferred embodiment according to the invention are represented by curve A. The frequency responses of a device with two Wheels and a parameter of 30 feet are represented by curve B; it should be noted that the curve becomes one has identically repeating cycle, which is undesirable. Curve C represents a device with eight Wheels and a parameter of 30 feet, the distances are the same size between the wheels and the wheels are attached in pairs to the corresponding base supports are, which in turn are rotatably articulated in the Mit.te of their longitudinal extension. The curve D represents the Represents frequency responses of a device which corresponds to the device according to curve C, with the exception that at the former, the base supports are non-rotatably hinged at their respective centers.

According to FIG. 8 it can be seen that the Curve A marked invention has the lowest fourth of the ratio of output variable to input variable. It should be noted that curve A has no repetitive wave parts. The curve C characterized device, many having equal spaces between the wheels touching the ground and in which each of the basic supports is hinged at its center point, has the next lower size ratios from output variable to input variable compared to curve A.

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It is understandable that if the Parts that come into contact with the subsurface are attached to the base girders, which in turn are pivotably hinged at their center point, From a mathematical point of view, such carriers act like a computer, by adding the vertical movement of each wheel or skid and dividing by the number of wheels or skids. In other words, with such an arrangement, the influence of each wheel or skid is in Relation to the rotatable center of the base beam is minimal if the transmission ratios of the two runners or Wheels are the same, and all wheels or runners exert the same influence on the foot sensor. It is evident that if an even number of support members in contact with the ground is used, an equal influence is best can be achieved by attaching the support members in pairs to beams which are rotatable at their center are hung. Of course, the invention does not apply to the use of an even number of elements in contact with the ground Support members limited and just as little to runners or wheels. When an odd number is touching the ground Support members is used, then the design of the device according to the invention, which the various Has girder lengths and their articulation points, through which the girder ratios are determined, in such a way, that the support members exert an equal influence on the sensor.

Instead of the runners, of course, wheels or other suitable ones that are supported on the ground can also be used Parts are used. It goes without saying that the accuracy of the device according to the invention is proportional to the number of the parts resting on the ground is the lowest deviation or the lowest ratio from output variable to input variable becomes with the largest Number of such parts reached. The embodiment

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- 12 -

of the present invention has eight runners, a number which is preferred for practical reasons; however is the invention does not relate to a particular device The number of parts supported on the ground is limited.

It will be apparent that the present invention provides a new and improved level reference device such frequency responses that the balancing device of the road machine is operated to thereby lay a road surface of a desired high profile. With the present Invention, this aim is achieved in that the parts touching the ground in any Be spaced from each other and that these parts be arranged so that they exert an equal influence on the sensor.

The figure shows schematically a subsurface E with an unevenness E ¹ which extends 30 feet in the longitudinal direction of the movement of the road construction machine (9.1 ** meters). The roadway profile that can be achieved by the device according to the invention is indicated by the line F; it can be seen that the unevenness E ¹ is essentially leveled. The device identified by the curve B in FIG. 8 could produce a roadway profile, which is drawn in with the line G in FIG. A 30 foot rigid beam with no runners or wheels would result in a roadway profile corresponding to line H in Figure 2.

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Claims (8)

Claims 1.) Mobile level reference device, in particular for a road construction machine, characterized in that a horizontally extending, articulated carrier arrangement in the direction of movement of the road construction machine and level reference parts responding to the position of the carrier arrangement are provided, which are in contact with a balancing device provided on the road construction machine, and that for support on the carrier arrangement a plurality of individual support parts touching the ground is articulated, a larger part of the support parts being arranged in the longitudinal direction of the carrier arrangement at arbitrarily selectable intervals. 2. Device according to claim 1, characterized in that that the support parts in pairs at opposite ends of corresponding base supports, which one part of the Form support arrangement, are articulated and that each base support means in the middle of its longitudinal extension an articulated connection is rotatably articulated to another carrier, which is a further part of the carrier assembly form. 3. Device according to claim 2, characterized in that that the carriers have at least four basic carriers. 4. Device according to at least one of claims 1-3, characterized in that the carrier arrangement has four basic supports and the other supports a first support, the opposite ends of which attack on two joint connections and thereby with the 309822/0767 / fS " a corresponding pair of base beams are connected, and that the other beams also have a second Have carriers, the opposite ends of which correspond to the other two joints on the other Corresponding pair of base supports are hinged and that the level reference parts on the first and second carrier are stored. 5. Device according to at least one of claims 1 to 4, characterized in that each Support part is formed from a runner which is rotatably mounted on the associated base support. 6.- Device according to claim 4, characterized in that g e k e η η - ' draws that the carrier assembly approximately. 30 feet (9.14 meters) long. 7. Device according to at least one of claims 1 to 6, characterized in that the carrier arrangement a plurality of beams hingedly connected to the support members so that the support members exert the same influence on the adjustment device. 8. Mobile level reference device for a road construction machine, which has a horizontally extending, articulated carrier arrangement in the "direction of movement of the road construction machine and level reference parts responding to the position of the carrier arrangement, which are in contact with a balancing device provided on the road construction machine, in particular according to one of the claims 1 to 7, characterized geke η η is characterized in that the support arrangement comprises a plurality of articulating carriers and dai each other UAüb |?. r \ <* a n§u the ground-contacting - 15 - 309822/0767 7253787 Support parts are articulated on the carriers in such a way that all supporting parts exert the same influence on the sensors of the balancing device. Device according to at least one of Claims 1 to 8, characterized in that the carrier arrangement has four beams and also a first beam, the opposite ends of which in FIG the middle of the carrier length of a pair of carriers are rotatably mounted and that the carrier arrangement also has a second Has carrier, the opposite ends of which are correspondingly in the middle of the carrier length of another pair of carriers are rotatably mounted. - 16 - 309822/0767 Empty row